The present invention relates to an information service system which provides information service to particular persons and more particularly to an information service system which selects and provides information which is especially important to participants in (users of) an object system.
In recent years, attempts have been made in transportation systems, plants and the like to transform intellectual activities of experts for system driving or controlling into algorithmic forms One of such attempts involves use of a fuzzy control method wherein the subjective ambiguity of people is quantitatively classified into fuzzy sets to determine control instructions. As examples of fuzzy theory controls, a scheme which relies on experts' estimation of system controls has been employed in controlling a cement kiln or in controlling the dose of chemicals to be provided in a water cleaning bed. The outline and applications of fuzzy controls are described in detail in IEEE Spectrum, Vol. 21, No. 8, pp. 26 to 32, Aug. 1984.
The present inventors have proposed a predictive fuzzy control scheme which determines a control instruction based on estimation of control objects sought by experts while using models of the object system, and this scheme is practically applied to automatic train operation and automatic crane operation (U.S. application Ser. No. 488,455, filed on Apr. 25, 1983, entitled "Method and device for stopping vehicle at predetermined position", now abandoned, from which we have filed a continuation U.S. application Ser. No. 127,549 filed on Dec. 2, 1987, both applications being assigned to the same assignee as the present application).
In line with developments of a highly sophisticated information system using new media, it has become important to provide a technology by which information really important to a user of (a participant in) the system is selected among a great amount of information and the selected information is supplied to the user, while aiming at supplying information which is comparable to that a skilled person would supply.
The above-described fuzzy control system aims at optimum control of an object system and gives a display of inferred results, an explanation of causes, and so on to a system participant. However, it does not positively provide information really desired by a system participant.
With conventional information services for an elevator operation system, a train operation system and so on, only a fixed message is supplied to a system participant when the object system reaches a predetermined condition However, such conventional information services are uniform or standardized so that meaningless or inferior information may sometimes be given to the system participant, who accordingly feels uneasy and restless.